Comfort layers are commonly used in seating or bedding products above/below a core, which may or may not include a spring assembly. Such comfort layers may include foam, fiber and gel products. U.S. Pat. No. 8,087,114 discloses a comfort layer made of pocketed springs. Such spring assemblies may be made of strings of individually pocketed coil springs joined or multiple coil springs joined by helical lacing wires.
Spring cores may be generally covered on the top and often on the bottom by pads of resilient foam as, for example, a pad of urethane or latex/urethane mix of foamed material. Within the last several years, more expensive cushions or mattresses have had the spring cores covered by a visco-elastic foam pad, which is slow acting or latex foam, which is faster acting than visco-elastic foam. That is, the visco-elastic foam pad is slow to compress under load and slow to recover to its original height when the load is removed from the visco-elastic foam pad. These visco-elastic pads, as well as the latex pads, impart a so-called luxury feel to the mattress or cushion. These pads also, because of their closed cell structure, retain heat and are slow to dissipate body heat when a person sits or lies atop such a foam pad-containing cushion or mattress.
Individually pocketed spring cores have been made with fabric material semi-impermeable to airflow through the fabric material, as more fully explained below. U.S. Pat. No. 7,636,972 discloses such a pocketed spring core.
European Patent No. EP 1707081 discloses a pocketed spring mattress in which each pocket has a ventilation hole in order to improve the airflow into and out of the pocket. However, one drawback to such a product, depending upon the fabric used in the product, is that the fabric of the pocket may create “noise”, as the sound is named in the industry. Such noise may be created by the fabric expanding upon removal of the load due to the coil spring's upwardly directed force on the fabric.
It is therefore an objective of this invention to provide a comfort layer for a seating or bedding product, which has the same luxury feel as a visco-elastic or latex pad-containing comfort layer, but without the heat retention characteristics of such a comfort layer.
Still another objective of this invention is to provide one or more comfort layers for a seating or bedding product having the same or a similar slow-to-compress and slow-to-recover to its original height luxury feel as memory foam.
Another objective of this invention is to provide a comfort layer for a seating or bedding product made, at least partially, with fabric impervious to airflow through the fabric, but which allows air to enter and exit the pockets at different flow rates in reaction to different loads being applied to one or more pockets.
Another objective of this invention is to provide a comfort layer for a seating or bedding product made, at least partially, with fabric impervious to airflow through the fabric, but which allows air to enter and exit the pockets via gaps in the seams of at least some of the pockets.